1. Field of the Invention
The present invention relates to an apparatus for fine grinding of material samples, especially mineral samples for laboratory experiments, and has a fixed grinding member and a rotating grinding member, which are disposed in such a way that a surface of each faces the other with a slight gap therebetween, with the material which is to be ground being received and passed between these surfaces.
2. Description of the Prior Art
Known fine grinding apparatuses having these features are the so-called grinding arrangements according to which the material is ground between two disk-like grinding members. The disks are either disposed horizontally or vertically, so that the axis of rotation of the rotating disks extends either vertically or horizontally. Among the oldest embodiments of such grinding arrangements are flour mills having grinding stones.
The grinding arrangements of the previously described state of the art are generally designed for production purposes and have a corresponding size. Due to the circular-disk-shaped chamber in which the material is ground, the introduction of the unprocessed material and the discharge of the fine material as such do not cause any particular difficulties; however, a differentiated control of the time the material can be retained in the grinding zone, and hence the possibility for achieving a wide range of the grinding degree, either cannot be achieved at all, or can only be achieved imprecisely. However, it is exactly these requirements which are required of fine grinding apparatus for laboratory experiments, where it is important to be able to explore or study series of many different samples under various conditions.